Up to now, the travel control apparatus has been developed to realize a vehicle control adapted to a road condition. For example, the travel control apparatus has been proposed which changes a target acceleration/deceleration according to a distance to an obstacle in front of the subject vehicle, and improves drivability and safety of a vehicle (for example, refer to PTL 1).
However, when a characteristic of the travel control for the vehicle is changed according to only the distance to the obstacle, the change may not meet an actual road condition and a driver's feeling. For example, in the situation where the obstacle is present on a subject lane, but a remaining road width is sufficiently large, or in a situation where the obstacle is present in front of the subject lane, but present on an opposite lane, but not on the subject lane, it is conceivable that a driver passes through the obstacle at an unchanged vehicle speed without conducting a speed reducing operation. However, the conventional art has a potential to change the vehicle characteristic even in such situations, and provide the driver with a feeling of strangeness.
In view of the above circumstance, for example, a travel control apparatus has been proposed which controls the travel characteristic of the vehicle according to the situation around the subject vehicle (for example, PTL 2). Specifically, the travel control apparatus includes an obstacle detection unit that searches a given area in front of the subject vehicle, and detects an obstacle in front of the subject vehicle, a residual road width calculation unit that calculate a residual road width at a position where the detected obstacle is present, and a vehicle characteristic change unit that changes the vehicle travel characteristic on the basis of the calculated residual road width.